This invention relates generally to bearings with rolling elements and, more particularly, to bearing seals for rolling element bearings having a variety of inner bearing ring configurations.
Various sealing structures have been provided in rolling element bearing assemblies to retain lubricant and to exclude debris and other contaminates. In particular applications, the inner ring of such bearing assemblies may be required to have a specific axial length different from that of other applications for the same bearing size. One well known bearing assembly configuration for such applications is illustrated in FIG. 1, wherein inner ring 10 extends axially outward as axial extension portion 11 to a length greater than that of outer ring 12.
As illustrated in FIG. 1, sealing structure 14 closes annulus 16 between inner ring 10 and outer ring 12 to retain lubricant within the bearing assembly and to prevent entrance of contaminants to rolling elements 18 and bearing races of inner ring 10 and outer ring 12. In the configuration illustrated, rolling elements 18 are balls within annulus 16, separated and held by retainer (or cage) 20. Sealing structure 14 comprises a metal bearing shield (or cap) 22 and a resilient seal member 24 which is deformable against cylindrical outer portion 26 of inner ring 10, as shown.
Bearing shield 22 has an axially outwardly extending deformable lip 28. During assembly, bearing shield 22, with resilient seal member 24 bonded thereto, is positioned against shoulder 29 of outer ring 12 as shown, and a conically shaped tool is pressed axially against deformable lip 28 to flatten it into a loop configuration 30, as shown in phantom. During such deformation, loop configuration 30 is moved radially outwardly into engagement with annular groove 32 within the bore of outer ring 12 to retain bearing shield 22.
Although such sealing structure adequately retains lubricant and excludes debris, the configuration requires expensive grinding operations, special tooling to provide the "roll crimp" flattening of deformable lip 28, and, in some cases, an additional staking operation to prevent rotation of bearing shield 22 with respect to outer ring 12. Because a rolling element bearing of a particular size may be required with an inner ring 10 having a variety of axial lengths, a wide variety of inner rings must be manufactured, inventoried and processed to produce the bearing assemblies.
The foregoing illustrates limitations known to exist in present sealing structures for bearings with rolling elements. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.